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The way in which human-made acids in the atmosphere interact with the dust that nourishes our oceans has been quantified by scientists for the first time. In the international study led by the University of Leeds, researchers have pinpointed how much phosphate “fertiliser” is released from dust depending on atmospheric acid levels. 3 Greek researchers participate in the team.
Phosphorus is an essential nutrient for all life, and when it falls into the ocean, it acts as a fertiliser that stimulates the growth of phytoplankton and marine life. The new study allows scientists to quantify exactly how much phosphate “fertiliser” is released from dust depending on atmospheric acid levels.
As well as researchers from Leeds, Georgia and Haifa, experts from three institutions in Greece, one in Israel, one in Germany and two others in the UK worked on the findings, published in Proceedings of the National Academy of Science.
The Greek researchers are Stelios Myriokefalitakis, Maria Kanakidou, and Athanasios Nenes.
Maria Kanakidou is a Professor of Computational Environmental Chemistry at the Environmental Chemical Processes Laboratory, Division of Environmental and Analytical Chemistry of the Department of Chemistry in the University of Crete.
Athanasios Nenes is a Professor at the Georgia Institute of Technology. He is also a visiting professor at the Faculty of Physics in National and Kapodistrian University of Athens and an affiliated researcher of ICE-HT/FORTH (Patras, Greece), while working with the National Observatory of Athens.
Stelios Myriokefalitakis is at the Environmental Chemical Processes Laboratory, Division of Environmental and Analytical Chemistry of the Department of Chemistry in the University of Crete.
Dr Anthony Stockdale, from the School of Earth and Environment at Leeds, is lead author of the study. He said: “The ability to quantify these processes will now allow models to predict how pollution on a global scale modulates the amount of fertiliser released in airborne dust before it falls into the oceans.
“Many regions of the globe are limited by the amount of phosphorus available, so pollution can have a very important impact on marine ecosystems.”
Co-author Professor Athanasios Nenes, of Georgia Institute of Technology, said the implications went beyond the carbon cycle and climate.
“The Mediterranean is one of many locations of the globe where pollution and dust mix frequently,” he said. “This study points to one more way this interaction can affect marine life and the 135 million inhabitants of its coastline.”
Phosphorus is one of the essential elements for life and is a critical component of building blocks such as DNA. Dusts, from deserts such as the Sahara, are an important source of phosphorus to Earth’s oceans. The mineral-containing dust is generated in copious amounts during storms and is found throughout the atmosphere. Most of the phosphorus in this dust is in an insoluble form that the microscopic plants of the oceans — phytoplankton and diatoms — cannot get at. Known as apatite, the phosphorus in the dust is similar to the substance found in our teeth and bones.
Acids can be released naturally into the atmosphere from volcanic eruptions and from living organisms. But the burning of fossil fuels is currently the most significant source of atmospheric acids. In the same way that acid produced by the bacteria in our mouths can cause tooth decay, so can acids in the atmosphere dissolve apatite and turn it into a form of phosphorus that can be used by marine organisms, the study authors said.
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